emilsuuri, at this stage of the game, I doubt you have found a processor bug, but it certainly is possible. I do not think there is expertise in this User Forum to help you. I do certainly not understand your code segment. I suggest you talk to AMD Online Support. Good luck and enjoy, John.

Ah , you are using assembly code . Intel have very careful IA 64bit assembly guide when i still in the unversity . Your code remind me of the old time . As i can remember , each cpu family has change in register when in 32 bit to 64 bit . Maybe you should find document clearly state about amd cpu register . Just , it is like you are learning system programming or you are trying to produce virus ! . But i wish you are learning system programming with assembly ! . But this is the hardware forum . Wrong place for software programmer ! . You should find your answer in stackoverflow forum . That is the place that you will find answer very easily . This is the hardware forum . Little software programmer is in here . Good weekend ! .

int 13h is interrupt command as the requirement before any execution of command . But very long ago nearly 10 years . Now i do not remember exactly . This reminds me of the time in the university with system programming .

that is a subject in the program in university . System programming . Now , no one has the time to write os . Linux is perfect and stable . Even russian military weapon , russian uses linux ! . and satellites all use linux . That is the catastrophic phenomenon if they use windows ! . A bug in windows can make satellites land on every body's heads ! . Funny ! . No certainly not .

The only purpose now is to write virus . And i hope that the asker does go that way ! .

Ah , write bios but i am not mainboard designer now . So i have no information in order to write program for bios . That is embedded system in deed ! . Write for chipset ! . That is really embedded system ! . Thank for your asking , hardcoregames . Have nice weekend ! .